Pauling diagram in electronic distribution

The Pauling Diagram, also known as the Energy Diagram, is the representation of electronic distribution through power sub-levels.

Through the scheme, the chemist Linus Carl Pauling (1901-1994) suggested something beyond what was already known regarding the distribution of electrons from the atoms of chemical elements.

To improve the mood, Pauling proposed the energy sub-levels. Through them, it would be possible to arrange the electrons from the lowest to the highest energy level of an atom in its ground state.

Electronic distribution by Linus Pauling

According to the model proposed by Pauling, the electrosphere is divided into 7 electronic layers (K, L, M, N, O, P and Q) around the atomic nucleus, each of which allows a maximum number of electrons, which are 2, 8, 18, 32, 32,18 and 8, respectively .

At electronics distribution the energy sublevels, showing the lowest energy electron first until reaching the highest energy electron.

Electronic Layers	Maximum Number of Electrons	Energy Sublevels
1	K	2 and^-	1s^2
2	L	8 and^-	2s^2	2p^6
3	M	18 and^-	3s^2	3p^6	3d^10
4	N	32 and^-	4s^2	4p^6	4d^10	4f^14
5	O	32 and^-	5s^2	5p^6	5d^10	5f^14
6	P	18 and^-	6s^2	6p^6	6d^10
7	Q	8 and^-	7s^2	7p^6

Layer K has only one sublevel(s), layer L has two sublevels (s and p), layer m has three sublevels (s, p and d) and so respectively.

The s sublevels allow up to 2 electrons, while the p sublevels allow up to 6 electrons. Next, the d sublevels allow up to 10 electrons, while the f sublevels allow up to 14 electrons.

Note that the sum of the electrons behaved in each sublevel per electron shell results in the maximum number of electrons in each of the 7 shells.

K: s² = 2
L and Q: s² + p⁶ = 8
M and P: s² + p⁶ + d¹⁰ = 18
N and O: y² + p⁶ + d¹⁰ + f¹⁴= 32

It was then that Pauling discovered the increasing order of energy:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p⁶

From there, the diagonal arrows appear in the diagram to make the electronic distribution of the elements:

Pauling diagram

Example of electronic phosphorus distribution ₁₅P:

1s² 2s² 2p⁶ 3s² 3p³

like up to 3s² we already had a total of 12 electrons (2 + 2 + 6 + 2), we only need 3 more electrons from the 3p sublevel⁶.

Thus, we can get the required amount of electrons, as long as it is not greater than 6, which is the maximum number that the 3p sublevel⁶ behaves.

Read too Valencia layer and Quantum Numbers.

Solved Exercises on Electronic Distribution

question 1

(Unirio) “Dental implants are safer in Brazil and already meet international quality standards. The great leap in quality took place in the process of making titanium screws and pins, which make up the prostheses. Made with titanium alloys, these prostheses are used to fix dental crowns, orthodontic appliances and dentures, in the bones of the jaw and jaw.” (Jornal do Brasil, October 1996.)

Considering that the atomic number of titanium is 22, its electronic configuration will be:

a) 1s² 2s² 2p⁶ 3s² 3p³
b) 1s² 2s² 2p⁶ 3s² 3p⁵
c) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
d) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d²
e) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶

See Answer

Correct alternative: d) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d².

The Linus Pauling diagram for the distribution of electrons in titanium is:

question 2

(ACAFE) Considering any generic M element, which has 1s electronic configuration² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵, it can be said that:

I. its atomic number is 25;
II. has 7 electrons in the last shell;
III. has 5 unpaired electrons;
IV. belong to the 7A family.

The statements are correct:
a) I, II and III only
b) I and III only
c) II and IV only
d) I and IV only
e) II, III and IV only

See Answer

Correct alternative: b) I and III only.

I. CORRECT Counting the number of electrons in the electronic distribution we see that 25 were used. Hence, the atomic number is 25 and corresponds to the chemical element manganese.

II. WRONG. The last layer, that is, the outermost layer has 2 electrons, being the 4s².

III. CORRECT The unpaired electrons are in the d sublevel, which holds up to 10 electrons, but in the electronic distribution of manganese only 5 electrons have been assigned to the sublevel.

IV. WRONG. Manganese is located in the 7B family and in the 4th period.

question 3

(UFSC) The number of electrons in each sublevel of the strontium atom (₃₈Sr) in ascending order of energy is:

a) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²
b) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 3d¹⁰ 5s²
c) 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s²
d) 1s² 2s² 2p⁶ 3s² 3p⁶ 4p⁶ 4s² 3d¹⁰ 5s²
e) 1s² 2s² 2p⁶ 3p⁶ 3s² 4s² 4p⁶ 3d¹⁰ 5s²

See Answer

Correct alternative: a) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s².

The Linus Pauling diagram for the distribution of strontium electrons is:

Test your knowledge even more! Also resolve:

• Exercises on Electronic Distribution
• Exercises on the Periodic Table